*{
  padding:0;
  margin:0;
   list-style:none;
 }
.tab{
    width:300px;
    height:300px;
    border:1px solid red;
    margin:100px auto;
   }
.tab input{
  width:100px;
  float:left;
  height:30px;
}
.tab .active{
  background:red;
  color:#FFF;
}
.tab li{
  width:300px;
  height:270px;
  background:blue;
  font-size:100px;
  text-align:center;
  line-height:270px;
  color:red;
  display:none;
}
.tab .show{
  display:block;
}
.tab section{
  overflow:hidden;
}
section input{
  background:pink;

}
a{
  color:yellow;
  font-size:50px;
  font-weight:bloder;
  position:absolute;
  text-decoration:none;
}
#tab3 a:nth-of-type(1){
  left:0px;
  top:130px;
  z-index:1;
}
#tab3 a:nth-of-type(2){
  right:0px;
  top:130px;
  z-index:1;
}
#tab3{
  position:relative;
}
